Git commits in Moodle 3.1.3 by Sam Wilson

commit 3aff88f24ccbf8a61e9e0b274f3a8f90ab89d5bd
Author: Sam Wilson <sam@samwilson.id.au>
Date:   Thu, 16 Jun 2016 20:40:13 +0800
Tag:    v3.1.3

MDL-29774 core_user: Update group-membership summaries on AJAX calls